基于HFCA的不对称酯类增塑剂的设计、合成及增塑机理研究

Plasticizer is one of the indispensable plastic additives in the processing of polymer materials. In recent years, phthalates that account for 80% amount of the plasticizers have been restricted in many fields due to their potential toxicity, so developing non-toxic and bio-based plasticizers with high plasticizing efficiency becomes an inexorable trend in plastic industries. It is an effective way to improve the plasticizing efficiency of the plasticizer by reducing its relative molecular weight, however, it will sacrifice its durability inevitably. To solve the above problems, 5-hydroxymethyl-2- furancarboxylic acid (HFCA) was firstly used as renewable raw material to explore new bio-based plasticizer with non-toxicity. Furthermore, a series of plasticizers with the same relative molecular weight and different symmetry were designed and synthesized by making full use of the molecular structure of HFCA, and the plasticizing efficiency of the plasticizer could be improved by adjusting the asymmetry of the alkyl chains on both sides. This design idea may increase the plasticizing efficiency of the plasticizers and keep their durability unaffected at the same time, and it is a new routing to optimize the comprehensive properties of the plasticizers. Finally, the plasticizing mechanism of the asymmetric ester plasticizers was expounded, which would provide theoretical and technical basis for designing excellent bio-based plasticizers in future.

增塑剂是高分子材料加工成型中不可或缺的塑料助剂之一。近年来，约占增塑剂用量80%的邻苯二甲酸酯类增塑剂因对人体具有潜在的毒性危害而被限制使用，开发无毒、高效的生物基增塑剂成为行业发展的必然趋势。在设计高效增塑剂的方法中，降低增塑剂的相对分子量可有效地提高其增塑效率，但同时也会牺牲其耐久性。针对上述问题，本项目首先以可再生的5-羟甲基-2-呋喃甲酸（HFCA）为原料，合成一种新型的环保型生物基增塑。在此基础上，充分利用HFCA的分子结构特点，设计并合成了一系列相对分子量相同且对称性不同的酯类增塑剂，在保证耐久性不变的条件下，通过调节增塑剂两端烷基链的不对称性来提高其增塑效率，从而实现增塑效率与耐久性的相互兼顾，为优化增塑剂的综合性能提供全新的研究思路。最后，阐明不对称酯类增塑剂的增塑机理，为今后设计综合性能优异的生物基增塑剂提供理论和技术基础。

以可再生来源的HFCA为原料，设计合成了一系列与邻苯二甲酸酯类增塑剂具有相似化学结构的生物基增塑剂，此类增塑剂对PVC表现出较好的增塑效果，具有替代石油基邻苯二甲酸酯类增塑剂的潜力；分别以2,5-呋喃二甲酸、2,5-呋喃二甲醇和HFCA为原料设计合成三种化学结构相似且分子量相同的增塑剂，发现增塑剂中酯基位置会影响与之相连的非极性烷基链的长度及自由体积，从而影响增塑剂的增塑效率；以HFCA为原料，设计合成了五种化学结构相似且分子量相同的不对称酯类增塑剂，发现增加增塑剂两端烷基链长度的不对称性，可以进一步提高增塑剂的增塑效率而不牺牲其热稳定性和耐久性；探索了不对称酯类增塑剂的增塑机理，为设计综合性能优异的生物基增塑剂提供新的理论。